Seems like your water injection project is a solution in search of a problem. I'd start off with the basics, fix the jetting and timing to get rid of the detonation. Then maybe look at a new/modified radiator setup to remove more heat from the head.

Seems like your water injection project is a solution in search of a problem. I'd start off with the basics, fix the jetting and timing to get rid of the detonation. Then maybe look at a new/modified radiator setup to remove more heat from the head.

If you have a very highly tuned race motor, which detonates due to very high compression, then if you can get methanol no problem, then why dont you run the bike on 50/50 methanol/petrol mix? This will mean no more detonation, and should provide a bit more power at the same time.

If you have a very highly tuned race motor, which detonates due to very high compression, then if you can get methanol no problem, then why dont you run the bike on 50/50 methanol/petrol mix? This will mean no more detonation, and should provide a bit more power at the same time.

i allready modyfied the radiators,i mounted 2 electric fans taken from a computers shop,i installed battery 4 them to work on the moto,another improovement i did was to install a electric water pump.the old water pump i had didnt supported high tures and breaked all the time(i had like 4 gears smashed in the engine-water pump gears).i tryed water methanol and also pure methanol today with my improvisation of instalation.the instalation i made its not good,its sprays too much compound,like 200 mililiters in 10 seconds ,but was fun to try it.i observed a improovement using methanol at idle.but at a point the engine stopped and i dismounted the carb to clean it,was full of water and methanol.oh,btw,today i felt verry sick because i sprayyed methanol with this instalation ,and i think i inhaled a bit.can be lethal,so dont play with methanol,anyway ,its illegal in most countryes.i think a good sistem can be done with water methanol but these compounds must be bottled in a high pressure recipe and with a verry fine nozzle (like spray cans have) that would increase the flow when engine gets high tures.

that would be the next thing to try,but methanol its expensive and illegal,i also expect to consume more fuel with 50/50 mix and probably somme carb problems...another thing in 50 50 mix is that i dont trust in methanol abilityes to lube the cillinder.rc planes that work on methanol use only ricin oil and a bit of nitromethane but they last just 2 hours

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I would suggest that if you cant get the fuel required to run your race motor successfully, that it might be a good idea to sell it and replace with something less highly tuned, which will run on pump fuel?

Not sure on methanol being illegal for race use though.............nitro methane is much nastier and is used in race applications all round the world!

The symptoms you describe are typical of (a) too much ignition advance and (b) a compression ratio too high for the ignition you're running.

As someone else posted, you have solutions looking for a problem.

Forget the methanol and water, and go back to basics for ignition timing and ignition system type. I'd also look carefully at whether your porting, head, and piston set-up make sense.

(FWIW, I've built TZ 250, 350, 700/750 Yamaha engines to produce - consistently - far more than the power the factory ever got out of them. None of the factories were stupid; it takes a lot of science to do better than they did.)

The symptoms you describe are typical of (a) too much ignition advance and (b) a compression ratio too high for the ignition you're running.

As someone else posted, you have solutions looking for a problem.

Forget the methanol and water, and go back to basics for ignition timing and ignition system type. I'd also look carefully at whether your porting, head, and piston set-up make sense.

(FWIW, I've built TZ 250, 350, 700/750 Yamaha engines to produce - consistently - far more than the power the factory ever got out of them. None of the factories were stupid; it takes a lot of science to do better than they did.)

i cant have problems with ignition!its electronic ignition,factory made(racing).i shortened the cillinder almost 20 milimeters because i installed a shorter biel that supports better high rpm than the stock one(long biel means morepower-couple but less rpm.when i run at high rpm it sounds like a boat or like as if its on nitromethane.all the changes i did to this engine are verry carefully studyed.when i ride my bike,it doesnt sounds like ,,brap brap brap,, it sounds like zzzzzzzz.for that.the compression is good,ignition also good,bad thing is that i cant find ,,good gassoline,, 4 it,i prepare high octane gassoline by myself adding naphtalene.the inconvenient is that after adding naphtalene to the gas i also ad a teflon oil that makes a lot of smoke(i cant drive with that on roads or in a city .

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Ignition.

All your changes (and the fuel) mean that a factory ignition curve will be totally irrelevant.